


Gold Sunlight and Deep Water

by justanotherStonyfan



Series: Random AUs [5]
Category: Captain America (Movies), Captain America - All Media Types
Genre: Beaches, Clit Dick, Hand Jobs, Handwaving, Human/Mermaid Sex, Hypersensitive genitalia, Interspecies, Interspecies Relationship(s), Interspecies Romance, Interspecies Sex, Languages, M/M, Mermaid Sex, Merman Steve Rogers, Non-Human Genitalia, Overstimulation, Penetrative Sex, Semi-Public Sex, Wet & Messy, Xeno, merfolk, mermaid Steve Rogers
Language: English
Status: Completed
Published: 2020-05-24
Updated: 2020-05-24
Packaged: 2021-03-03 00:28:16
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 7,520
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/24355825
Author URL: https://archiveofourown.org/users/justanotherStonyfan/pseuds/justanotherStonyfan
Summary: Steve's a merman, Bucky's a human, and they have mer-sex on a private beach, and do not get spied on, interrupted or discovered.
Relationships: James "Bucky" Barnes/Steve Rogers
Series: Random AUs [5]
Series URL: https://archiveofourown.org/series/727680
Comments: 74
Kudos: 255





	Gold Sunlight and Deep Water

**Author's Note:**

  * Inspired by [Blue Scales](https://archiveofourown.org/works/3347195) by [chaya](https://archiveofourown.org/users/chaya/pseuds/chaya). 



> Happy Mermay Y'all! 
> 
> Thanks everyone in the chat who put up with my internet issues and helped me with words! 
> 
> **Spoilery summary is in the end notes below.**

Steve has always draped himself over everything like well-crafted jewelery. All those paintings, all those stories, all are true.

Bucky lounges back against rock and basks in the sunlight because he can, water up around him but not for his modesty. There's none of that left now, not in the slightest, and Steve watches him cast scattered light across the sand with the arm.

Because Steve, Steve is artfully draped with the fingers of one hand tracing idle patterns against Bucky's chest, his eyes half closed, the water swirling slowly about his tail. His other hand supports his head, his pale skin flushed at his cheeks and showing color in his flanks. His hair shows the last remaining traces of color by the roots, the rest dry and standing in wispy, salt-stiff tufts of white. Mer hair is hollow, transparent with the color in its core. White and stiff in the air, it turns diaphanous and colorful underwater, like jellyfish tendrils around his head. He keeps it short for practicality but, if he weren’t a fighter, it would be down to his tail by now. 

Bucky brushes it for him often anyway, but now’s not the time. Now, the line of nubs that run from behind his ears to the center of his collarbone are raised slightly, and Bucky knows what he'd see if they weren't lounging in the sunlight.

“Mmmmwwant,” Steve murmurs, his voice low and thick. 

He always forgets his English if he's happy enough.

“Hmm,” Bucky says. “Pal, you know you don't even gotta ask.”

Steve's eyes flash as his grin spreads, and his teeth are getting a little translucent, growing a little sharp, but that's all right. Bucky likes 'em a little sharp. 

Steve makes a soft, high, chattering noise in the back of his throat and turns onto his back in the sun, extends his arms, hands, tail, and stretches with the kind of sound deep in his chest that makes Bucky's blood run warm as Steve leaves imprints of his scales in the sand beside him where he lay a moment ago. Bucky watches, always fascinated, as color blooms upward from Steve's hips, a dappled blue that crawls from the scales there like smudged oil pastel and travels upward to envelop the outsides of his torso, of his arms, shoulders, the sides of his throat, framing his face as it creeps into his hair. Like a zipper, his green-blue spines, joined by thick, translucent membranes, grow from their hiding places on his forearms and blend into his wrists, beautifully shaded iridescence between his fingers, elongating along the shells of his ears and fading into his jawline. 

The fins along his iliac crest grow and darken, almost with a life of of their own, shifting restlessly as they begin to show below his navel, pushing out from between his scales there until they meet themselves in a 'v', rich with seagreens and royal blues, shamelessly drawing the eye as it's meant to do. Steve long ago lost any shame in showing his pelvic ruff to Bucky.

Where his skin flushes, his sea-colouring wars with his human, so that skin that should be blue and would be pink turns lilac with arousal, and his eyes darken as he crosses his wrists above his head, the oldest sign Steve’s people have of supplication. And when Bucky sits up to lean over him, Steve's chest expands, the lacy gills along his jugulars opening just enough that Bucky sees. The smaller frills over the sides of his ribcage darken, too, closer to the lilac across his chest and near violet of his nipples. Bucky knows that, where the scales dip low, low against the curve of Steve's belly at his front, they climb so high at the back that they're almost to the middle of his spine, and his dorsal fin stretches upward from his tail all the way to the knot at the base of his neck. The skin of a Mer’s back is heard and leathery, like sharks or rays - trust is different for them. 

Where Bucky’s met many a man he didn’t trust, Bucky’d tell you _you wouldn’t turn your back on a man like that,_ but Mer? Mer would turn their backs on anyone until they knew that particular someone could be trusted.

Steve chatters again with muscles in the back of his throat, and arches his back as he flutters his tail flukes just below the surface of their little rock pool, the water sparkling as it dances off the vibrating skin and cartilage. It's another sign of supplication, another invitation borne of Steve's species – fluttering his tail flukes in the water as a signal to proclaim both his readiness and his possession of a partner, displaying his pelvic ruff and his gills with the arch of his back, for the same reason he raises his limbs – to expose his anterior with all the vulnerabilities there simply by keeping his spines out of Bucky's way.

Bucky has seen Steve's Mer mating responses many times, but it's never any less beautiful and, mingled with the more human aspects of Steve's arousal, it's downright sexy. Steve's Mer responses are quick and unashamed, colorful and deliberate in their evolution. But his human responses – the shortness of breath, the restlessness, the way his parted lips are redder than his nipples because he's bitten them that way, the clear arousal he shows in each breath and each twitch and each bitten-off moan…

“Want,” he whispers, and his flukes flutter again.

Bucky's hard – got hard when Steve's ruff bloomed, when his markings spread – but Steve presses his fists into the sand over his head and arches his back even further with a desperate keen that he makes down in his throat somewhere. It isn't enough to be a Song, not to Bucky.

He says something in Mer, then – a whispering hiss past teeth that are still sharpening, like a wave against shore, which Bucky knows from experience is the singular-personal in Steve's dialect for _please_ as an entreaty. It's stronger than the request form, more intimate than the formal and informal, and it's meant for individuals, not a pod. Bucky loves that, too – that learning Mer may be learning three languages in one, but one of those is specially for the two of them. Words that the formal and informal never contain, phrases that mean more just by their structure, and all the beautiful things that mean they give themselves to each other with such unfailing love, with something so much deeper than human, that they have no translation.

 _‘Bucky!’_ he breathes, like water against rock, and Bucky trails the backs of his fingers down the center of Steve's exposed torso and back up again. “ _Hah_ -ah, ahh,” Steve says, his body twitching as Bucky's fingers follow the line from Steve's sternum to his navel and back.

He bites his lip and squeezes his eyes shut and makes himself rigid to show Bucky his assent, holds his body open to Bucky's will with his arms stretched and his tail extended and his shoulders back to broaden his chest. From a creature whose back is armored - and Steve's is, beautifully - there is no greater trust than the exposure of his underbelly.

Bucky brushes the ribcage frills and Steve's breath hitches, the dappled blue darkening as he fights the undulation of his tail – Bucky can see the muscles shifting under his skin, under his scales.

“Sweetheart,” Bucky tells him, “baby doll, look at you.”

“Buc-keee,” Steve answers on a whine, his lashes damp, his expression pained, and Bucky can see the jagged line, perhaps the length of the span of his own hand, that runs vertically between the scales where the pelvic ruff conjoins.

“Pretty baby,” Bucky murmurs, his fingertips feather-light around one violet nipple until it puckers, turns crimson like its twin against the almost white of Steve's skin, “all this softness, look how bare you are, look how open...”

Steve bites his lip, a row of little points that press the soft, pink flesh of his lower lip.

“...so vulnerable...”

Steve shivers, a head-to-toe vibration that lives in his bones until Bucky is good enough to coax it out, and his head falls back as Bucky draws his fingers down, down to meet the edge of his skin, where the scales begin, and the jagged line lies.

Bucky uses caution because he has to – he must be gentle in touch and in words; Mer like different things said to them than humans, Mer's anatomies aren't the same.

“You're so,” he says, bending his head to Steve's chest, breathing over the white softness of skin bared to nobody but him as his fingertips trace the parting in Steve's scales, “so...”

He bites, hard, across the sweet, puckered skin of Steve's nipple, incisors digging in with as much pressure as he dares, and Steve's mouth opens on a piercing cry that Bucky knows doesn't come from his human larynx. Mer pierce the skin on purpose, their pain receptors linked differently, and they talk of First Blood when it comes to sex (so Steve told him once, a long time ago). Some even bear ritual scars, but this, so Steve says, is an old practice. Bucky cannot sharpen his teeth, but Steve doesn't love him any less because of it, if the desperate pitch of his human voice is anything to be believed. 

“That was a loud one, huh?” Bucky murmurs, tracing Steve's parting with his fingertips, back and forth, back and forth.

“I'm soh-” Steve gasps, “I'm sorry-”

“Oh, sugar,” Bucky tells him, nipping at his skin, leaving little pink marks on the underside of Steve's white pectoral, “don't gotta tell me you're sorry for whistlin’, not at all.”

Steve's head thrashes on the sand when Bucky bites him again, worrying the nipple between his teeth this time and, this time, Bucky eases the tips of his fingers into the parting in Steve's scales, where the flesh is soft and slick. Steve can't help his convulsion, fingers clawing backward into the sand as his mouth opens, eyes wide and blue from corner to corner. No sclerae, not for him, not now.

“Yes!” he gasps. And then more Mer - _“ 'take, it's yours,' ”_.

He can't harm Steve like this – scales are like fingernails, but stronger, more deeply rooted – they won't bend or break, Bucky can't hurt them, not from rutting against them, not from grinding down. He doesn't even, really, need to be cautious of the spines – they might jab, but they aren't weapons unless Steve wants them to be, aren't venomous unless Steve makes them so. And so Bucky straddles his tail, the scales thick and blunt between his legs, ridged against his cock, to look down at him, fingers rubbing the ruff at Steve's hips, so that Steve's cheeks flush and his chest flushes and the ruff darkens further as blood rushes there. Steve moans, mouth open as he arches his back again.

Bucky pushes his fingers into the parting – he keeps his nails short for this reason and this reason alone – into soft, yielding flesh and the slickness Steve's body makes and, slowly, he strokes his fingertips over the harder ridge of flesh within before he pauses. He waits as Steve trembles, as Steve gasps for breath, until Steve's tail moves hesitantly down in the water, bending back, a presentation of himself to Bucky's willing hands though his body fights against the movement, sensation too strong though it's everything he wants.

He leaves himself open to Bucky like this, in a way he never can be below the waves. Mer evolved to copulate underwater, in a sea full of harsh minerals and many kinds of life. Steve's body produces its own lubrication so that the water can’t cause friction, but Bucky learned a long time ago that, for Steve, the sensation of being exposed to air instead of water, and of being exposed by human hands instead of immediately sheathed in a partner, is different enough that he craves it.

Steve's reproductive organ isn't a clasper, it isn't a hectocotylus – there isn't enough information on Mer for it to be classified, but Bucky calls it a cock despite its shape, despite its texture. And he knows it's sensitive – more sensitive than a human's. It has to be. It was never designed to be met with anything but another Mer. Mers mate like dolphins – belly to belly, tails pressed together – but it's the press of a pelvis that causes the response, which is the press that Bucky will mimic. If Steve were to mate with another Mer, their body would receive him without him ever being exposed to the water.

“Here,” Bucky says, laying his palms either side of the parting, and Steve stares up at him, his eyes so blue and his desperation so plain, “let me.”

And then he pushes against Steve's scales, and outward, so that the parting opens and the flesh inside eases forward, slick and soft and purple at the base by his scales, through to red at the tip. It juts out like a thick hook, blunt at the end and almost conical except for its upward curve. The tissue is thick and fibrous – Bucky knows how sensitive it is, almost all nerve.

Steve moans, keens, half-sobs as Bucky exposes him, coaxing the organ from its internal sheath.

“Bah-” he says, “ah- _huh,_ kee-”

“It’s alright,” Bucky says, “how’s that, small fry, huh, ready for a little more open water?”

Steve moans softly. It’s second nature to talk to him now where it used to be confusing, where it used to be difficult to remember. Once he called Steve ‘roe’ and Steve didn’t speak to him for nearly a day, it was agony. But he doesn’t mind small fry, Bucky can get away with ‘fingerling’ if Steve’s in the right mood. 

“Look at these frills, sweetheart,” he says, and lets his fingers drift along the fluttering pelvic ruff, just avoiding touching Steve’s blunt, jutting cock, just away from it, only just. 

Steve says, _Soulmate,_ in mer, just as plaintively as the entreaty, but they’ve got as much time as they need, and Steve never really wants him to hurry - not even when they’re making human love, although Steve’s not nearly so sensitive then. Steve’s fists are digging holes in the sand - he won’t participate until Bucky tells him to, he wouldn’t if Bucky were Mer either. When you can hurt so easily, you have to be sure your advances are wanted. It’s actually kinda nice, Bucky thinks - with all the terrible things he’s seen and been through, and all the awful things the people of the world do to each other, it’s underwater hybrids scared of movie screens and automobiles who can school humanity on how to ask a guy right for a little love. 

“I love you, honey,” he says, tries a little Mer for himself - _“ ‘pretty baby,’_ look at those colors,” and Steve laughs, low and throaty and trilling. 

Bucky knows he’s used _infant_ by mistake, instead of…well, it doesn’t really mean _baby_ but it’s a term of endearment that means _one I wish to do everything for_ so he can be forgiven for mixing the two up in his head given that they sound similar and they’re similar lengths in Mer. Steve doesn’t mind anyway.

 _“ ‘Pretty baby,’ ”_ he says, correctly, but he’s not correcting Bucky, he’s more sort of saying it for himself, an echo of Bucky’s affections, trying it on for size as though he can’t quite believe that it’s true. 

Steve turns his arms inward and out again, inward and out again, his spines catching the light as they do - the color doesn’t quite pulse but the spines are designed like prisms, and they seem to flash color when he moves. 

Bucky has a surprise for him. 

When Bucky first cut his hair back to Steve’s length, a year or so after Insight, Steve had kissed him senseless, cradled his head and circled him and - Steve doesn’t dance, not the way Bucky does, but he winds his body close whether he has legs or a tail at the time. And so Steve had been enjoying the water, catching the sunlight with his scales and his spines, when Bucky had come into the water with him and then, well. Then Bucky could see how tales would abound of Mers drowing sailors - if he hadn’t known it was Steve, hadn’t trusted Steve implicitly, he might have been afraid. _“ ‘Mine, mine, mine, like me! Us! US!’ ”_ Steve had chittered, swimming around him like a helter skelter, corkscrewing his whole self about Bucky’s body. 

Bucky has spent a lot of time color matching. He knows Steve’s colors anywhere, greens and blues, violet and lilac, he knows what shade of which acrylic paint to buy, knows which threads to weave, he knows which fabrics show which dyes best and, speaking of dyes, Bucky can’t change his color. He can’t make his skin come up in dappled hues or turn his vulnerable places into displays of lust and pleasure. He can’t make patterns in the dark or be the bright point in the sun, but they’ve come a long way together - they’ve lived a long time together - and there are things that hair stylists can do now that they never could when he was a child and Steve was a pup. And it won’t last, of course. Not with salt water and bright sun as their getaway of choice, but Steve’s taken time with pigments to draw the dapples on Bucky’s body for himself, he’s given him jewelry and accessories to wear whenever he can (there’s a reason Bucky asked for his blue peacoat back from the Smithsonian, and that reason is that Steve’s eyes turn a certain color when he fights, and Bucky will wear it with pride for the rest of his life). Steve likes his colors on Bucky’s body, and Bucky’s done the same for him. One of his tags, trinkets that match Bucky’s eyes (apparently - Steve’s eye for it is much better than his own) and any number of little things that Steve’s adopted just because he wants Bucky as part of himself. The way he stood in uniform, the turn of phrase he developed. All of it’s been, really, an exercise in being each other, and Bucky loves wearing Steve on himself almost as much as he loves Steve. 

Steve learned to screw his eyes up when he laughed, learned to chew the inside of his cheek when thinking. It’s all involuntarily voluntary, and Bucky will show him what he’s done in a little while, when they’re a little further along. 

Steve’s slick, is the thing. His cock doesn’t need to be brought out, Bucky can sink his fingers into the parting of his scales and do it that way, gentle fingers and thick heat. There’s enough room for movement that Bucky’s cock can fit inside the parting with Steve’s if they want, snug alongside with proximity and friction to pleasure them both. The scales around the parting, at the base of Steve’s cock, are already slippery with it, and Bucky sucks his fingers to make sure they’re wet enough that they won’t catch. He can’t be sure enough of his grooming that the tiny little callous edges or dry skin won’t scrape - Steve’s like the princess and the pea when it comes to this kind of touch, but his cock is nerve and fiber, exposed and sensitive. It’s as though he has too few layers of skin on it, as though it’s new, and pleasure can so easily turn to pain if Bucky isn’t careful.

Still, Steve whines as Bucky sucks his fingers, body rolling from hip to tail. He still has his scars, he’ll bear them for the rest of his life, but in the patches of smooth leather left as reminders between the scales, in the beautiful, sensitive gap in the spines that comprise his dorsal fin, Bucky’s hands and mouth always fit perfectly. 

“Hmmm,” Bucky hums, because he can’t Sing, not like a Mer, and plays at the edges of Steve’s ruff once more, gentle fingers, a tease because they have the time to tease. 

“Mmh,” Steve answers, and then pulls his lips back from his cloudy-glass-like teeth, “Buh,” those sounds are hummed too, and Bucky leans close, and breathes near to him. 

Steve’s breaths are cool, his teeth sharp and far from opaque - it makes his mouth look like a chasm beneath glass needles - but he’ll wait. For Mer, the receiving partner is the dominant one until copulation really starts - foreplay is an exercise in restraint for the other, a test of will to prove devotion. And so Steve won’t participate until Bucky shows that he’s satisfied, won’t move from his position until Bucky makes it clear that he’s passed the test. It’s never been an issue for Bucky, and isn’t really necessary, but Steve likes it, it’s instinct for him, easily indulged in an act that’s based so heavily on instinct as it is. And so he lies in the sand with his fists digging deeper and deeper over his head with Bucky over him, one hand in the sand, the other free to touch. Bucky brings himself close, and then licks his palm, gets it good and wet without taking his eyes off Steve’s. 

Then he cups the head of Steve’s cock, smooth and dark, and slowly turns his hand.

Steve’s whole body goes tight as a bowstring, his eyes shut tight, his tail curls and his flukes curl, and his spines come sharp, the flesh about them receding. 

_“Mh!”_ he gasps, a bitten-out sound that’s high and desperate. 

Not bad for being treated like a lemon juicer. 

When they first did this, years before, it was over before it started. Bucky barely eased his fingers into Steve’s parting before they were done, and then Steve was twitching in not-quite-pain and begging Bucky to stop. The first time Bucky managed to coax him from his sheath was much the same - Bucky did to Steve what he liked for himself, and it was too much and it was too fast and Bucky nearly lost his hearing in one ear from the whistle Steve’s Mer larynx made in shock. 

Now, he knows better. 

He keeps his fingers featherlight and gentle, brushes them against the smooth curve of Steve’s cock and back, shifts his attention from the underside to the top, from the base to the tip. It still won’t take long, but they’ll actually get to enjoy it. 

“With me?” Steve whines on a breath. “In with me?” but it’s never easy to sheathe him again once he’s erect and coaxed out, and they’ve got as long as they want to go again later.

“Next time, sweetheart,” Bucky tells him, stroking his fingertips over the tip of Steve’s cock before he does the same at the base where the scales line it. “Get all snug and warm in there with you, huh?”

“Buc-kee,” Steve says, plaintive as always, so Bucky ducks his head and bites at Steve’s pecs again, and then lifts his head and scrapes his teeth over the little raised nubs behind his ear, down his throat.

Steve shivers strongly enough that the water foams around his flukes, and he opens his fists in the sand and digs his fingers in. 

“Better wash those ‘fore you get ‘em on me,” Bucky tells him, because they both know that everlasting love does nothing to negate sand on your genitals during a vigorous handjob, regardless of how dexterous your lover’s fingers are.

“Buh, Bu-ah, Buc-kee,” Steve says, and Bucky bites him hard - makes a red ring around his right nipple and then nips the skin between his front teeth.

Steve’s chest expands and a whine hums deep in his chest, high and piercing though he’s bitten it back for Bucky’s benefit. 

“Remind me to bring earplugs next time,” Bucky says, and Steve thrashes his head on the wet sand.

“Please,” he says, “please _please!”_

“Whassamatter baby?” Bucky asks, fingers still shifting, and Bucky knows how to deal with a dick because he owns one - Steve gets one too when he’s in human form - but this ain’t a dick, not really.

With a dick, the head is sensitive - with this thing, the whole thing’s a singing nerve, a razorblade of pleasure from root to tip. 

“Please Buc-kee, please, it’s not- Is too-”

“You want my mouth on it, baby?” he says, and Steve draws accidental arcs in the sand with the fingers as he fights to keep his hands dug down in supplication instead of grabbing for Bucky. 

_“ ‘Uncharitable,’ ”_ he hisses in Mer, a real hiss, deep and full and broad like the _hiss_ of an orca’s blowhole, and Bucky laughs half in shock and half in delight.

“Okay!” he chuckles. “Okay, I’m sorry, you’re right. You’re right, I’m sorry.”

“Give meee,” Steve says, and lifts his head but not his hands, and he’s doing so well, he’s doing _so well._

“Can have it, huh?” Bucky says, and he lowers his voice so it’s like a secret between them. “Can have you, can have me?”

“Us,” Steve answers. _“ ‘Us,’_ Buc-kee, _‘please,’_ ” and Bucky nods slowly, leans in for a kiss.

“Watch your teeth,” he says, and then opens his mouth and slants it down over Steve’s and Steve _is_ careful with his teeth. 

“Ohn,” Steve groans into Bucky’s mouth as they finally come together.

Bucky can feel them pressing against his lip when he tries for shorter kisses, and sand be damned - Steve _loves_ to touch. Bucky’s seen him tear men limb from limb and strip the meat from their bones with his teeth, he’s seen him poison attackers in moments with movements as fluid as water, he’s seen the other half of his soul do everything mortally possible to cause pain and destruction without mercy to the people who hurt them most, and yet he knows, as soon as he brings their mouths together, how this is going to go.

Steve doesn’t disappoint - he plunges both long-fingered hands into Bucky’s hair and scrapes his scalp with his elongated fingernails. The goosebumps rise on Bucky easily, and he smiles into the kiss - gets his lip nipped a little but that’s his own fault - as he hitches his hips up against Steve’s tail. It’s nice to get a little friction, nicer still to listen to the little clicks in Steve’s throat that Bucky can feel vibrating through his own skull. 

“Which hand?” he asks, and his blood is on Steve’s lips, Steve’s eyes are wide and blue and his face is full of color and he pants like he does when he forgets his human self can’t hold his breath as long.

“Give. Me,” he says, but Bucky’s finished foreplay, there’s no need for Steve to be the submissive party any longer.

There’s no whining this time, no keening supplication, no plea, no cry - just a voice as deep and dark as the depths of the ocean, resonant like a crashing wave, and Steve’s eyes unblinking. Even without pupils, Bucky knows when he’s being stared at. He’ll use the flesh hand because the metal hand is mostly smooth, and sharp in the other places. But his skin, his real skin, has fingerprints and knuckle wrinkles, and Steve can feel every single one.

He smiles down at Steve where Steve lies in the sand, stares right back at him, and turns his head a little in Steve’s grip. He sees the moment Steve spots it. Steve goes from languid possession to fiery lust in a heartbeat, as Bucky’s movements shift his head, his hair sliding through Steve’s fingers. The smile drops away from Steve’s face, the heavy-lidded arousal turned to wide-eyed ferocity as his mouth falls open, and then he’s scrubbing his sandy fingers through Bucky’s hair, where the peekaboo highlights the lady at the salon half-did for him show green and blue in the underlayers that aren’t visible through Bucky’s dark hair otherwise. 

“How?” Steve rumbles, pushing and pulling at his hair. “How? Dye? Hooow?”

“Yeah, I got it bleached,” Bucky says. “And then I colored it. It won’t last forever, I’ll have to have the bleach redone, I’ll have to recolor it. But It’s called peekaboo highlights, the underneath is dyed but the top is normal so nobody knows unless-”

“For me?” Steve says, somehow even more incredulous. “Only for _me?”_

“Only for you, sweetheart,” he says, “prettiest, shiniest sweetheart, only for you-”

Steve looks like he might burst from amazement, he scrunches his fingers through Bucky’s hair as he looks at the colors, and then pushes Bucky’s head to one side so he can part Bucky’s hair with both hands. Bucky laughs.

“My,” Steve says, “mine, you picked mine-”

“Always pick yours,” Bucky says, and Steve nods, face twisting - and that’s another wonderful thing about him. 

Bucky knows that twist in his expression - Steve is overwhelmed, Steve is happy and amazed and grateful. Steve loves him so much that it almost hurts him to love so deeply, and Bucky knows because he loves Steve back just the same. 

“I- I know,” he says, “you always pick mine, I always pick yours, I love- Buc-kee, I love you, we,” and here it comes, the pural ‘I’, _“ ‘I love,’ ”_ he says, because that’s the other thing about Mer podspeak. Steve and Bucky are steveandbucky. The plural ‘I’ is _both souls at once._

Bucky’s heard Steve say their Mer portmanteau once or twice. It’s reserved for vows, for occasions, for life and death and moments more intimate than anything shareable with the outside world, and Bucky _can’t quite_ pronounce it yet (just like he’ll never be able to pronounce the name that they assembled ‘Steve’ from really, all wave sounds and dolphin noises, with a hiss and a click and a cry and a crash close enough that it all just about sounded like a loud, confused “sssTeeeeeeEEEEE _FFF_?” right there in the middle if you used artistic license), but this, the name Steve’s made for them, the name they share, sounds like the way the sea would sound like a breath if the wave came in gentle over sand and pulled back hard and deep from shingle, as the air came clean into your lungs. The plural ‘I’ is less than that, but always would have been less - no word is as strong in Steve’s tongue than the word they make together. But it’s still a summer day of sound inside Bucky’s mind, like the foam that crackles transient on a sun-baked shore, in the wake of an ebbing tide.

“I love you,” Bucky says, and tries to say it in Mer the way Steve did, with the ‘I’ that means ‘we’, _“ ‘I love,’ ”_ and Steve’s hands slow, his head tilts slowly. 

_“ ‘I love,’ ”_ he says again, a murmur, reverent, a pact. _“ ‘I love.’ ”_

And, for a long few moments, that’s all they need, that’s all they want. Sun and sand and privacy and proximity. And then Bucky says,

“Want me to love a little harder?”

And Steve snorts, searches Bucky’s hair a little more. 

“Want all of you,” Steve answers, a little more coherently than Bucky was expecting, to be honest. 

And so he decides it’s time to remedy that. 

Steve makes a noise Bucky can’t even work out in his head - it’s closer to sounding _aqua colored_ than anything like a sound, and he’s not even going to try making sense of that one - but he makes it because Bucky curls gentle fingers around his cock without warning him first, and Steve thrashes on the sand beneath him, fingers going tight in his hair before he gets it under control and lets go. 

His head goes back, one shoulder comes up, and his mouth drops open on a groan that lights Bucky’s blood on fire.

“Yeah?” Bucky says, and Steve flexes his body up to meet him, thick, ridged scales against Bucky’s cock while Bucky touches Steve’s as lightly as he can.

“Yes!” Steve hisses, face screwed up against the onslaught of pleasure. “Yes!”

Bucky starts to roll his hips against Steve’s scales, the motion eased by the slick that spreads between them. As far as analysis is able to provide, (and wasn’t it a mortifying ordeal to find out?) the slickness is a number of things, oil and protein strains and something to do with one of the components of Steve’s blood, but it works, and it’s harmless to both of them, and it eases the way just enough that Bucky’s grinding up on texture instead of something more akin to a cheese grater. 

There is a scaleless patch of skin the size of a quarter, where Steve is missing three scales that will never return, and it sits perhaps seven inches below the end of Steve’s parting. There is a matching patch almost identical to it on the back of his tail, too and, while the flesh has knitted there from the wound that pierced him through, Bucky runs one thumb over it, rubs in circles for a long few moments. Steve’s hands are on Bucky’s shoulders because the nails are sharp and scratches on Bucky’s shoulders are better than ones on his scalp. 

“Please,” Steve grits out, his teeth are meshed perfectly but the sound still comes through. “Buh-” he can’t speak for gasping, and so Bucky sets his fingers in a ring around Steve’s cock and strokes him that way, from base to tip in one smooth motion. _“Oh!”_

Steve’s body convulses, and his nails dig into Bucky’s skin. For a moment, his grip is unyielding, his strength a rival to Bucky’s metal arm, but then one hand slips down while the other pulls, and Bucky finds himself hitched close to Steve’s body, long fingers tucked up where his ass meets his thigh to angle him _just so._

“Hurry,” Steve tells him, and Bucky laughs.

“What, you think you’re gonna go too slow otherwise?”

“Not me,” Steve answers, desperate and strained. “You! Hurry!”

But Bucky understands. He strokes with the ring of his fingers once more, tries to imagine how it would feel for Steve if he could last long enough for penetration in his Mer form, and speeds up the motion of his hips to chase an orgasm that, he knows, is probably much further away than Steve’s.

“Uhn, please,” Steve says, his head back, his eyes closed, his tensions growing greater with every passing moment, and Bucky can’t help it.

He tries so hard to enjoy the present, to remember they’re here because they’ve come so far but so often, when they’re like this together, alone and happy, he remembers what they’ve been through to reach this point, what they’ve both had to suffer to make one more stroke through the water, to put one foot in front of the other. 

“Love you,” he says, that ring of his fingers traveling light and fast once more, “love you, sweetheart,” and Steve gasps, his sharp teeth bared, his long lashes down, his hands gripping Bucky tight like they might float away without each other to hold, and then-

Steve makes a high, keening whistle, mouth open, loud enough to make Bucky wince, and that’s his cue - Bucky closes his fist tight and squeezes and-

Steve makes a long string of sounds that might be English or might be Mer or might just be his body responding to what he feels. His whole body vibrates with it for a long few seconds, and he goes stiff as a board all over before his cock collapses in Bucky’s hand, fluid rushing out, tail undulating under him as his flukes vibrate in the water. There’s no opening to be seen on Steve’s cock, no head, no steady stream when he comes, the organ just collapses in Bucky’s hand like a sponge squeezed of honey, if honey were the same lilac as Steve’s skin can be.

The first time, Bucky’d been _terrified_ , convinced he’d somehow damaged Steve beyond recovery. Now he knows better, and squeezes rhythmically as the syrupy fluid seeps out over his fingers, his fist, Steve’s scales, the once-hard organ turning spongy, until Steve’s gasps turn pained, until Steve’s hand snatches his own away. The organ is much smaller now, more like a miniature tentacle than the stiff, engorged, blunt cone of before, and rests innocuous on his scales. They’re not really sure how it works - same principle as an erection, also same principle as as a clitoris, also same principle as a sea sponge and an octopus tentacle - who cares how it works anyway?

“Bucky,” Steve gasps, chest heaving, and Bucky smiles, leans down better to kiss him.

It’s long and sweet, Steve’s not a huge fan of tongue, not really, and Bucky can live with that - he can use his tongue in other ways, and _Steve_ , whose tongue is near prehensile, is also eye-rollingly talented with it in other departments. And so Steve just lies in the sand with his hands tight on Bucky (yes they’ll bruise him, no Bucky doesn’t care) and kisses back.

By the time Bucky pulls away and looks down, Steve’s cock is dusky and flaccid between them, like a little pink squid limb, and it’s slowly retracting even while Bucky watches. 

He chuckles - can’t help himself - and looks back at Steve’s face. Steve looks _very_ smug.

“Pretty good,” he says, “for weeks- for- uh, for. Weeks?”

“Pretty good considering it’s been a couple of weeks,” Bucky says - Steve’s human speech centers aren’t fully back online yet - and Steve snorts. 

“Prit-good consideris been coupleweek,” he slurs, and then _“ ‘perfect, beautiful, deep and happy, good, good, best-good,’ ”_ he chatters in Mer, and grabs for Bucky’s head again, rubs his nose over Bucky’s nose, pretends to nip at Bucky’s lips but uses his own lips instead of his teeth. 

Bucky hums into the affection and strokes Steve’s ear membranes between his fingertips, follows the nubs down to his collarbone once Steve gives him the leeway.

“Ahhhh,” Steve answers, smiling with all those teeth as his head tips into Bucky’s touch, and Bucky follows his hand with his mouth, cups his palm over the skin to see the way the nubs glow blue. 

“Look how lit up you are,” he says, and Steve trills softly. “Put you in the dark sometime, see what I have to do to get you to light up the room.”

Steve makes another little whistle noise but this one’s carefully controlled - a happy little noise of ‘that sounds nice.’

“You,” Steve answers. “Bucky, come on, Buck, I- _‘finished, I finished, you,’ ”_ and the thing is that Bucky doesn’t _need_ an orgasm to enjoy himself with Steve, but one sounds pretty nice right about now.

They’re both covered in Steve’s come, the transparent, syrupy slick that’s so abundant that it’s winding zig-zagging tracks down between Steve’s scales and dripping off him into the sand. God, he makes a mess - Bucky’s only tried to swallow once, and loves Steve very much, but the sting of seawater up your nose when someone sneaks up on you and grabs your ankles underwater has _literally nothing_ on whatever it is that Steve’s producing. Steve says maybe it’s because he’s venomous and there’s a component of his blood in there with the fluid, but Bucky’s not convinced - it’s never done any harm to anywhere else on his body, he’s probably just got a sensitive nose. And regardless, he loves that it gets everywhere - maybe that makes him weird but it’s true.

“Now,” Steve says softly. _“Now_ in with me,” and he lets go of Bucky to mimic the press with his own hands, pushing either side of his parting to open the scales for Bucky.

Bucky bites his lip and looks down at it, dark and wet and- He really can’t resist, not when Steve asks like that, and a little white’s coming back to the corners of Steve’s eyes as he does, he definitely knows what he’s asking.

“You sure?” Bucky says, because he’s sensitive all over right now, and sensitive inside the parting more than anywhere else. 

_“ ‘In with me,’ ”_ Steve answers, and he lifts his head from the sand to murmur it against Bucky’s ear like distant waves on a summer’s night. 

Bucky lines himself up as best he can, but he doesn’t need to be overly careful - it’s probably terrible of him to think of this as home, but that’s what it feels like. Being inside Steve’s body this way feels like nothing else that Bucky knows, especially with his dick a little roughed up from the scales, and Steve makes a tense, throaty sound when Bucky’s cock settles into the hollow inside of him. Steve calls it something that doesn’t translate, and Bucky calls it a parting because that’s as close as he can get, but his cock fits inside perfectly, the scales hard and shifting around the base of his cock as Steve’s body comes to accommodate him. 

It’s soft and smooth and wet and snug, and Bucky can feel Steve’s heartbeat through the walls of it - Steve’s heart has to beat strongly given that his tail is all muscle and his heart has to keep him warm in deep ocean - but there’s no grip, it’s not like that. There isn’t anything like this, not really.

“Oh fuck, Steve,” he breathes, and Steve gathers him close, wraps his arms around Bucky’s body and pulls Bucky’s head down to his chest with one hand on the back of his skull. 

It’s protection, Bucky knows that. Steve’s arms cross his back to cover his spine, Steve’s hands shield his head and cover the cleft of his ass, because Steve spines are good for warding off attacks, and those are the most vulnerable places on Bucky when Bucky’s on top of Steve and fucking into him.

“Sandy fingers,” he warns, a little unsteadily, and Steve hums a laugh against the side of Bucky’s head. 

“I know,” he says, because he’s only forgotten himself and tried to finger Bucky with sandy fingers once, and they’ve both resolved to be vigilant in making sure that it never happens again. _“ ‘Come home.’ ”_

And Bucky groans into Steve’s neck and fits his hands to Steve’s shoulders, and rolls his hips into snug, wet heat. It’s good, it’s always good, and Steve curls his fingers just a little - not enough to get sand into awkward places, but enough to wake the nerves a little, enough to spread Bucky’s cheeks just a fraction. The air around them isn’t cold, but any air’s cool on skin that spends most of its time inside clothes and hidden by other skin and muscle, and Bucky finds sometimes that it feels like such a strange dichotomy to work so well: He loves Steve more than anything, there’s nothing more intimate than this and, at the same time, there’s nothing more animal than the way Steve’s instincts and his own come together. It’s how they are, he supposes, how soulmates are meant to be - that the basest things their bodies want can be so loving, can be such a passionate expression of ardor. 

It doesn’t take long for Bucky either, not really. They’ve been apart for two weeks and he’s already watched Steve come undone under his hands, and it feels so good - Steve is heat and pleasure where the sea air is crisp and fresh on his back, and rutting into Steve - in whatever form Steve’s taken - has always been exactly where Bucky wants to be at all times.

“Ah, Steve,” he says “Steve,” and he can’t quite do it, his larynx won’t quite make it, but he knows Steve’s real name, the one he has in Mer, and he can approximate it well enough that Steve will understand. _“ ‘Please,’ ”_ as an entreaty, for individuals, not a pod, “Steve,” he says, _“ ‘Gold Sunlight at Evening (that shines on white crests of the waves)…’ ”_

And Steve smiles against Bucky’s ear as Bucky comes, and make a gentle little sound, not like a Song but like a Lullaby - it’s a balm to Bucky’s mind and all the jagged edges that live there, blue bioluminescence to the flickering shadows that still hide in the recesses of Bucky’s memories. Steve holds Bucky close and rocks him gently, like a ship on the water, and Bucky lets him, legs tucked up astride Steve, buried inside of him like he never has to be anywhere else, shielded by his soulmate’s spines, and nestled skin to skin.

“Hmm,” Steve says, and trills low in his throat, soft and gentle with affection and satisfaction. _“ ‘I love,’ ”_ , that plural ‘I’ that soothes Bucky’s soul, and then he and his spine-laden arms hold Bucky close, while his talented tongue whispers the name that Bucky chose for himself when they found each other again, to bring him truly home. _“ ‘I love,’ ”_ he says, _“ ‘my love,’ ”_ a whisper, _“ ‘Deep Water in Moonlight (that holds all the dark of the sea).’ ”_

**Author's Note:**

> This nearly had a Joke Title. Until the last paragraph, it was going to be called “Pisces Libra (et homo)” which, badly translated, would have meant, “Fish Scales (and Man)” but even more loosely translated would have meant fishdude and gayboy. 
> 
> I might come back to this in future, as I’ve always wanted to write Mer-Steve vignettes. 
> 
> Spoilery summary (not that there’s much to spoil): Bucky and Mer-Steve have their approximation of sex. This involves dominant/submissive behavior to start as per Mer traditions, then a handjob, then penetrative sex. Because of the nature of the Mer anatomy I’ve written, Steve’s whole body becomes more Mer when he gets aroused - he grows spines, his ruffles and fins get fancier, his colors change, he gets bioluminescent spots on his body in certain places. When it comes time for sex, Steve both gets and erection and then, later, when his erection subsides, has an internal hollow that Bucky can penetrate. It’s not a vagina, but then his dick isn’t really a dick either. For reference, Steve’s dick looks like a giant pointed clitoris, and it comes like a shampoo ginger, or just a whole sponge cone full of syrup. Squish spludge, enjoy that image - you’re welcome.


End file.
